Street Trees. 



317 



injured. In localities where severe wind storms are prevalent, the 

 evergreens suffer quite as much as the deciduous trees, because the 

 resisting surface is greater at that season of the year when such storms 

 do the most damage. Along the seashore, most of the trees are deformed 

 and usually lean in the direction opposite to that from which the pre- 

 vailing winds come. Protection can be given best only by a correct 

 selection of deciduous 

 trees, and by keeping 

 from conifers the heavy 

 loads of snow which break 

 the branches during the 

 winter. In many city 

 parkS; and along avenues 

 that are Hned with very 

 large and old tall-growing 

 trees, it is the custom to 

 cut oft" a part of the tops, 

 thereby lessening the dan- 

 ger both to the tree and 

 to the public. There is 

 seldom any justification 

 for this, and until such 

 time as the parts of a 

 tree are knovrn to be dan- 

 gerous, they should not 

 be cut. Keeping a tree 

 free from dead wood will 

 nearly always overcome 

 this danger. 



(5.) Freezing. 



Winter-killincr of trees ^^'^- 235. — A unique method of preserving an old 

 . ,1 rr . c c (^^d valuable specimen of willow. 



from the effects 01 ireez- 



ing, and the splitting of the tininks from the same cause, form the basis 

 for many inquiries on the care of trees. The greatest danger from 

 freezing lies not in the fact that many trees in a normal condition of 

 growth are killed back, but rather that improper pruning and unpro- 

 tected wounds cause cavities to appear on the trunk and larger 

 branches; these fill with water during the summer months, and during 

 the winter months the ice formed in them splits seams up and down 

 these parts of a tree (see Fig. 238). These seams or cracks, small at 



